Herein, nickel sulfides are synthesized through solvothermal–hydrothermal method. It is found that nickel sulfide can be prepared by controlling the amount of thiourea. The phase composition and particle size of nickel sulfide can be controlled by adjusting the amount of thiourea, so as to adjust the corresponding electrochemical properties. Experiment results show that proper phase composition and small particle size of nickel sulfides are thought to contribute to the impressive electrochemical performance and multiple charging/discharging process can minish the performance gap among the different electrode materials.
